Torsional hinged mirrors are now being used as scanning mirrors in laser printers to provide a beam sweep or scan of the image of a modulated light source across a photoresist medium, and as pointing mirrors for redirecting a light beam to one or more specific locations. Devices supported by torsional hinges, other than mirrors may also benefit from this invention. Torsional hinged devices that use silicon for the hinges provide excellent performance at a very advantageous cost and with a very long life, since material fatigue is almost non-existent in torsional hinge devices made of silicon. Magnetic coupling between a permanent magnet on a torsional hinged structure and an electrical coil positioned close to the permanent magnet may be used to provide a drive force to pivot or oscillate the device, or the electrical coil may generate an output signal as the magnet moves with respect to the coil. The output signal will be indicative of the rotational position of the torsional hinged device.
However, as will be appreciated by those skilled in the art, the drive force resulting from electrical signals applied to the electrical coil, or the sensed electrical signals generated as the permanent magnet moves with respect to the electrical coil diminishes as a function of the square of the distance between the magnet and the electrical coil.
Therefore, methods and structures that reduce this distance without a corresponding decrease in structural strength or an increase in complexity or cost would be advantageous.